1 /*
2  * OMAP4 SMP cpu-hotplug support
3  *
4  * Copyright (C) 2010 Texas Instruments, Inc.
5  * Author:
6  *      Santosh Shilimkar <santosh.shilimkar@ti.com>
7  *
8  * Platform file needed for the OMAP4 SMP. This file is based on arm
9  * realview smp platform.
10  * Copyright (c) 2002 ARM Limited.
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License version 2 as
14  * published by the Free Software Foundation.
15  */
16 
17 #include <linux/kernel.h>
18 #include <linux/errno.h>
19 #include <linux/smp.h>
20 #include <linux/io.h>
21 
22 #include "omap-wakeupgen.h"
23 #include "common.h"
24 #include "powerdomain.h"
25 
26 /*
27  * platform-specific code to shutdown a CPU
28  * Called with IRQs disabled
29  */
30 void omap4_cpu_die(unsigned int cpu)
31 {
32 	unsigned int boot_cpu = 0;
33 	void __iomem *base = omap_get_wakeupgen_base();
34 
35 	/*
36 	 * we're ready for shutdown now, so do it
37 	 */
38 	if (omap_secure_apis_support()) {
39 		if (omap_modify_auxcoreboot0(0x0, 0x200) != 0x0)
40 			pr_err("Secure clear status failed\n");
41 	} else {
42 		writel_relaxed(0, base + OMAP_AUX_CORE_BOOT_0);
43 	}
44 
45 
46 	for (;;) {
47 		/*
48 		 * Enter into low power state
49 		 */
50 		omap4_hotplug_cpu(cpu, PWRDM_POWER_OFF);
51 
52 		if (omap_secure_apis_support())
53 			boot_cpu = omap_read_auxcoreboot0();
54 		else
55 			boot_cpu =
56 				readl_relaxed(base + OMAP_AUX_CORE_BOOT_0) >> 5;
57 
58 		if (boot_cpu == smp_processor_id()) {
59 			/*
60 			 * OK, proper wakeup, we're done
61 			 */
62 			break;
63 		}
64 		pr_debug("CPU%u: spurious wakeup call\n", cpu);
65 	}
66 }
67